public void Undo(Calculator receiver)
{
if (results.Count > 0)
results.Pop();
if (results.Count > 0)
receiver.SetCurr(results.Peek());
else
receiver.SetCurr(0);
}
public void Compute(Calculator receiver, string @operator, int operand)
{
// Create command operation and execute it
Command command = new ElementaryArithCommand(
receiver, @operator, operand);
command.Execute();
commands.Add(command);
results.Push(receiver.GetResult());
}
